diff --git a/package-manifest.toml b/package-manifest.toml
index 4472f12dd28..6a2311c4dc2 100644
--- a/package-manifest.toml
+++ b/package-manifest.toml
@@ -122,7 +122,7 @@ source.type = "local"
 source.rust.binary_names = ["nexus", "schema-updater"]
 source.rust.release = true
 source.paths = [
-  { from = "/opt/ooce/pgsql-13/lib/amd64", to = "/opt/ooce/pgsql-13/lib/amd64" },
+  { from = "/opt/ooce/pgsql-18/lib/amd64", to = "/opt/ooce/pgsql-18/lib/amd64" },
   { from = "smf/nexus/manifest.xml", to = "/var/svc/manifest/site/nexus/manifest.xml" },
   { from = "smf/nexus/{{rack-topology}}", to = "/var/svc/manifest/site/nexus" },
   { from = "out/console-assets", to = "/var/nexus/static" },
@@ -132,7 +132,8 @@ source.paths = [
 output.type = "zone"
 setup_hint = """
 - Run `cargo xtask download console` to download the web console assets
-- Run `pkg install library/postgresql-13` to download Postgres libraries
+- Run `pkg install library/postgresql-18` to download Postgres libraries
+- Run `pkg set-mediator -V 18 postgresql` to select the library version
 """
 output.intermediate_only = true
 
@@ -528,10 +529,14 @@ source.type = "local"
 source.paths = [
   { from = "smf/switch_zone_setup/manifest.xml", to = "/var/svc/manifest/site/switch_zone_setup/manifest.xml" },
   { from = "smf/switch_zone_setup/support_authorized_keys", to = "/opt/oxide/support/authorized_keys" },
-  { from = "/opt/ooce/pgsql-13/lib/amd64", to = "/opt/ooce/pgsql-13/lib/amd64" },
+  { from = "/opt/ooce/pgsql-18/lib/amd64", to = "/opt/ooce/pgsql-18/lib/amd64" },
 ]
 output.type = "zone"
 output.intermediate_only = true
+setup_hint = """
+- Run `pkg install library/postgresql-18` to download Postgres libraries
+- Run `pkg set-mediator -V 18 postgresql` to select the library version
+"""
 
 [package.sp-sim]
 service_name = "sp-sim"
diff --git a/tools/install_builder_prerequisites.sh b/tools/install_builder_prerequisites.sh
index 646c764f8e9..f8d6358722e 100755
--- a/tools/install_builder_prerequisites.sh
+++ b/tools/install_builder_prerequisites.sh
@@ -145,7 +145,7 @@ function install_packages {
     fi
   elif [[ "${HOST_OS}" == "SunOS" ]]; then
     CLANGVER=15
-    PGVER=13
+    PGVER=18
     packages=(
       "pkg:/package/pkg"
       "build-essential"
@@ -239,12 +239,12 @@ function show_hint
   case "$1" in
     "pg_config")
       if [[ "${HOST_OS}" == "SunOS" ]]; then
-        echo "On illumos, $1 is typically found in '/opt/ooce/bin'"
+        echo "On helios, $1 is typically found in '/opt/ooce/bin'"
       fi
       ;;
     "pkg-config")
       if [[ "${HOST_OS}" == "SunOS" ]]; then
-        echo "On illumos, $1 is typically found in '/usr/bin'"
+        echo "On helios, $1 is typically found in '/usr/bin'"
       fi
       ;;
     "cockroach")
diff --git a/tools/install_runner_prerequisites.sh b/tools/install_runner_prerequisites.sh
index af438257f92..7661b95bf08 100755
--- a/tools/install_runner_prerequisites.sh
+++ b/tools/install_runner_prerequisites.sh
@@ -112,7 +112,7 @@ function install_packages {
   if [[ "${HOST_OS}" == "SunOS" ]]; then
     packages=(
       'pkg:/package/pkg'
-      'library/postgresql-13'
+      'library/postgresql-18'
       'pkg-config'
       'brand/omicron1/tools'
       'library/libxmlsec1'